<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    
    var message = 'Global Message'
    function foo() {
      var message = 'Foo Message'
    }
    var num1 = 10
    var num2 = 20
    var result = num1 + num2
    console.log(result)

  </script>
</body>

</html>